Releasable knob for a lock

ABSTRACT

A releasable knob for a lock having a body adapted to be installed in a door panel and having a hollow spindle rotatable in the body about an axis to operate a lock bolt, has an inner knob member mounted on the spindle and secured thereto against relative rotation about the axis and against axial movement thereon. An outer knob member substantially encloses the inner knob member and is rotatable relative thereto about the axis but is not axially movable relative thereto. If desired a lock mechanism may be disposed partly in the spindle and partly in the inner knob member. A locking bar, preferably sliding in an axial slot in the spindle, is movable between one position coupling the inner and outer knob members and another position decoupling the inner and outer knob members. Preferably the locking bar is spring urged in one direction and is manually returned or operated from the side of the lock opposite the releasable knob.

United States Patent [1 1 Tornoe et al.

[451 Dec. 24, 1974 RELEASABLE KNOB FOR A LOCK Inventors: John A. Tornoe,Redwood City;

Curtis A. Dyer, Belvedere, both of Calif.

Schlage Lock Company, San Francisco, Calif.

Filed: Apr. 9, 1973 Appl. No.: 349,241

Assignee:

US. Cl. 292/336.3, 292/352 Int. Cl. E05c 1/00 Field of Search 292/l69.14347, 348, 352,

References Cited UNITED STATES PATENTS 7/1873- Whipple 292/352 2/1967Reed 292/347 X 2/1973 Tornoe et al. 292/352 X Primary Eiamirier -RichgdE. Moore Attorney, Agent, or Firm-Lothrop & West [57] ABSTRACT Areleasable knob for a lock having a body adapted to be installed in adoor panel and having a hollow spindle rotatable in the body about anaxis to operate a lock bolt, has an inner knob member mounted on thespindle and secured thereto against relative rotation about the axis andagainst axial movement thereon. An outer knob member substantiallyencloses the inner knob member and is rotatable relative thereto aboutthe axis but is not axially movable relative thereto. If desired a lockmechanism may be disposed partly in the spindle and partly in the innerknob member. A locking bar, preferably sliding in an axial slot .in'thespindle, is movable. between one position coupling .the inner and outerknob members and am other'position decoupling the inner and outer knobmembers. Preferably the locking bar is spring urged in one direction andis manually returned or operated from the side of the lock opposite thereleasable knob.

11 Claims, 13 Dravving Figures PATENTED DEC 2 4 I974 sum 3 at 5 PATENTEU05824 I974 sum u or 5 RELEASABLE KNOB FOR A LOCK In the ever increasingdemand for improved security in locks,- particularly. for doors, therehas of late been added emphasis on the utilization of a knob or otherhand actuator, usually on' the more vulnerable side of the door, whichis capableof being coupled to and decoupled from the lock bolt actuatingmechanism, preferably with a control for the coupling or releasingmechanism available onthe less vulnerable side of the door. While thereare locks already available with re-.

leasable knobs, these usually require a special design of lock toaccommodate the releasable knob and often involve rather elaborate andexpensive mechanism to achieve the desired function. Furthermore, someof the releasable knobs are technically released from the actuatingmechanism but can even so be manipulated in such a fashion as to producelock operation.

It is therefore an object of the invention to provide a releasable knobwhich is relatively simple and inexpensive in construction.

Another object of the invention is to provide a releasable knob whichreadily can be incorporated with locks already manufactured.

Another object of the invention is to provide a releasable knob that isnot readily defeated or coupled when it is technically decoupled.

' A further object of the invention is to provide a re leasable knobthat to most externalappearances is substantially identical with knobsnot having the releasable feature.

A further object of the invention is to provide areleasable knobquicklyshiftablebetween coupled and decoupled conditions.

' A further object of the invention is to provide a gen- I 11 is a viewcomparable to FIG. 5 showing a modified form of key bar in position withassociated parts, theview being in cross-section indicated by the linesl1'11 of FIG; 12;

FIG. 12 is a cross-section, the plane of which is indicated by the line12'-l2 of FIG. 11; and

FIG. 13 isan isometric perspective showing in exploded position some ofthe components of the form of releasable knobillustrated in FIG 11.

In the customary environment the releasable knob is utilized inconnection with a lock 6 mounted on a door panel 7 adapted to swing, inthe customary fashion, so

' as to move the panel 7 toward and away from a door jamb 8 in which astrike plate 9 and strike box 11 are installed. The lock 6 includes onthe interior orless vul- V nerable side an inner trim or escutcheon 13surrounding the shank 14 of an inner knob 16 rotatable about atransverse axis l7-extending through the entire lock. Rotation of theinner knob 16 is effective. through standard mechanism, not shown, toretract and permit the projection of a latch bolt 18 projecting from theedge of the panel 7. The latchbolt preferably also operates with a deadlatch plunger 19.

Mounted on the opposite, more vulnerable or exterior side of the panel 7is a similar trim 21 surrounding a lock casing 22 fixedinthe panel 7 andserving as the journal mounting foranouter, hollow spindle 23. Thespindle is disposed to rotate about the axis 17 and preferably includesa hollow tubular member having at one end a latch bolt or lock boltoperating mechanism 24 of any suitable, standard sort. The spindle 23customarily is rolled from a sheet of metal and has an axially extendingslot 26: throughout the length thereof. The slot is largely defined bythe spaced faces of the rolled material of the spindle. The hollow ortubular'spindle has a predetermined, outside, circular diameter and apredetermined, inside, circular diameter, the latter establishing whatmay be termed the bore 27 of the spindle-The spindle is preferably somounted as to extend in a cantilever fashion from a location within thepanel 7 and casing 22 to an exterior point remote therefrom.

' Pursuant to'this embodiment of the invention there FIG. 3 is across-section, the plane of which is indicated by the line 3--3 of FIG.1;

FIG. 4 is a cross-section, the plane of which is indicated by the line4-4 of FIG. 1; a FIG. 5 is a view similar to FIG. 1 but showing amodified form of releasable knob containing a pin tumbler lock unit; 3

FIG. 6 is a cross-section, the plane of which is indicated by'the line6-6 of FIG. 5;

FIG. 7 is a detail showing in plan a two part key bar;

FIG. 8 is an isometric perspective showing a different form of key barin position with an inner knob member;

FIG. 9 is an exploded view showing in perspective an outer knob memberwith the parts thereof axially separated;

FIG. 10 is an isometric view of a modified form of lock spindle and partof a two piece key bar assembled therewith;

.is disposed on the projectingportion of the spindle a first or innerknob member 31 (see especially FIG. 8)

having a central bore 32. This is of a size to slid'e easily in anaxialdirection on the spindle and to encompass a portion of theprojecting part ofthe spindle. The first knob member 31 is contoured toafford a cylindrical portion 33 separated'from a larger diametercylindrical portion 34 by a radial shoulder 36. The first knob memherhas a radial end face 37 joined to the cylindrical portion 34 by'amerging conical portion 38 and also has an extended neck 39 of reduceddiameter.

Extending'radially through the neck 39 is an opening 41 to receive aretaining plate 42 of the customary sort mounted for transverse motionacross the spindle. In oneposition, the plate 42 occupies not only theopening 41 but likewise .occupies a registering opening 43 in thespindle itself. When the plate 42 is in the position shown 'in FIG. 2,for example, it is effective releasably to secure the first or innerknob member to the spindle not only against relative rotation thereofabout the axis 17 but likewise against translation thereof in thedirection of the axis 17. In effect, the inner knob member is secured tothe spindle for operation therewith.

The first or inner knob member is not particularly adapted for handgrasping. There is consequently mounted on the inner knob member andsubstantially encompassing the same a second or outer knob member 46.This is a relatively thin shell, usually of metal, and is initially madein the form of an open cup. It is assembled onto a relatively heavy ring47 with which is united a relatively light cup 48 (see especially FIG.9). The ring 47 includes an interior band 51 designed to rotate readilyon the portion 33 of the inner knob member.

Around the band periphery, although not formed entirely thereth'rough,is a series of axially and radially extending notches 52, eight suchnotches being customary. The ring also includes a bearing portion 53designed to rotate readily on the cylindrical portion 34, there being ashoulder 54 between the band 51 and the bearing portion 53 designed foraxial abutment with the shoulder 36. The exterior of the ring 47 in thepresent instance is defined by a surface of revolution concentric withthe axis 17. This surface, in the present instance approximately of aspherical nature to match the similarly configured knob 46, can beconfigured, if desired, to match the cooperating portion of a handlever, also generally referred to herein as a knob. Comparably, the cup48, although relatively thin, is provided with a radial end wall 56designed axially to abut the end surface 37 and has an outerconfiguration 57 designed approximately to match the configuration ofthe exterior knob 46.

The members 47 and 48 are interfitted by the interengagement of the rim58 of the cup with a step 59 of the ring. Preferably, the ring and thecup are lightly press-assembled and then the initially cup-like outerknob member 46 is placed over them and is then spun or otherwise wroughtinto its final configuration, substantially as shownin FIG. 2. Aconverging portion 61 of the outer knob shell closely overlies andconfines the ring 47 and cup 48 so closely that the outer shell, thering and the cup form substantially a unitary member for independentrotation about the axis 17.

As a matter of appearance it is customary to provide a trim sleeve 62with a shank 63 overlying the neck 39 and with a flange 64 underlyingthe inturned portion 61 of the outer knob member. There is a smallaperture 65 through an appropriate portion of the trim sleeve'62 so thatunder proper circumstances tool access can be had to the retaining plate42.

In the present instance the shell of the outer knob 46 is closed in itsouter portion ,and'does not provide for any key mechanism. For thatreason it is preferred to assist in supportingthe partsand in holdingthem appropriately in position by'assembling a hollow plug'66 Iconcentric with the axis 17. The plug has an outer face 67 matching theadjacent contour "of the knob 46 and likewise has a step 68 abutting thecup 48 and assisting in centering the parts with respect thereto. Asmaller step 69 interfits with and closes the end of the spindle 23.

Although no key mechanism is provided it is considered that since theknob 46 is on the exterior of the door, it should-not readily beremoved. For that reason there is provided a plug 70 disposed within thespindle 23 and urged into position by a spring 75 also abutting the plug66. Theplug 70 has a central boss projecting into the path of the plate42. The plate 42 then cannot be moved radially inwardly by any toolinserted through the opening 65. If the plug 70 is moved axially away byan interior tool, the securing plate 42 can then be shifted radiallyinwardly and the knobreleased from the spindle.

In the assembled condition of the parts the second or outer knob 46together with the shell, related cup 48 and ring 47 is freely rotatablerelative to the first or inner knob member 31 about the axis 17. Norotary motion is transmitted to the spindle and to the interior workingparts of the lock despite the efforts of a person attempting to use thelock. The outer or second knob member simply rotates or spins withrespect to the rest of the mechanism.

In order that the usual turning function can be obtained when proper, aspecial mechanism is afforded. Advantage is taken of the axial slot 26customarily provided in the spindle 23. Lying within'that slot, asespecially shown in FIGS. 1, 2 and 3, is a locking bar 71. This can beof generally rectangular cross-section but since the adjacent edges ofthe spindle often are slightly converging, the locking bar itself mayhave converging walls, as shown in FIGS. 3 and 4. The locking barextends for almost the full axial length of the spindle 23. In itsaxially outer portion the locking bar71 is especially enlarged toprovide a radially directed, inclined Y jaw 72 (see FIG. 2) of aconfiguration slidably occupying an axial slot 76 in the inner knobmember 31 and readily able to enter into and substantially to occupy anadjacent one of the notches 52 when the jaw 72 is axially opposite thenotch.

The locking bar 71 with the outstanding jaw 72 can be moved axially froma position with the jaw 72 within the notch 52 into another positionwith the jaw 72 out of the adjacent notch 52, although remaining in theslot 76. This requires movement of the bar to the left, in FIG. 2. Thismotion is resisted by a coil spring 73 having one end seated in a cavity74 in the inner knob portion 33 and having the other end seated in asimilar recess in the locking bar. The locking bar is thus normallyurged to put the jaw 72 into an available notch In this relationship andsince the locking bar,being in the slot 76, cannot turn about the axis17 with respect to the first or inner knob member, the inner and outermembers are thus locked together for rotation in unison or are coupledfor rotation about the axis 17. Absent some exterior force and becauseof the force of the spring 73,.the outer knob member is usually coupledto the inner knob member. If they happen to bemomentarily uncoupled, aslight rotation of the outer knob with respect to the inner knobbringsthe jaw 72 into axial alignment with an adjacent notch 52 and thespring 73 produces an instant engagement and unitary locking of the knobmembers.

Since one of the objects of a spinning or releasable knob is to augmentthe security of a lock, it is preferably provided that the locking bar71 be operable from the opposite side of the lock; in the present casethat is from the interior side thereof.

Within the interior knob 16 there is provided an axi ally movable member77 or button that may or may not be locked in an axially displacedposition. This button 77 and adjacent parts are comparable to themechanism shown in US. Pat. No. l,579,457 issued to Walter R. SchlageApr. 6, 1926. When the button 77 is depressed it moves a bar 78 axiallyinwardly. In turn, this translates a transverse plate 79 engagedtherewith. The

- the influence of spring 73 so that the locking bar jaw 72 is in anadjacent notch 52 and the knob parts are locked together. When thebutton 77 is displaced inwardly (to the left in FIG. I)' the 'bar 78 istranslated downwardly as is the transverse plate 79. This engages theend of the locking bar71 and moves the bar 71 against the urgency of thespring so that the jaw 72 is removed from the notch 52 and the outerknob is decoupled or released from the inner knob 'for free spinmng.

Under most circumstances the resistance of the lock mechanism to motionis such that insufficient turning force can be transmitted by frictionbetween the uncoupled outer shell 61 and any of the interior parts toretract the latch bolt. However, if the inter-knob fric-' tion happensto be relatively great, for example, under relatively cold conditions,then the friction betweenthe inner knob, and the outer knob might besufficient to overcome the lock mechanism resistance and produce lockactuation. For that reason it is provided that the plate 79 not onlytranslates the locking bar toward locked condition and itself slides inthe slot 26 in the spindle but further enters into a notch 81 in thelock casing 22. In this way the spindle is positively locked by theplate 79 to the lock casing 22. No amount of friction between thetechnically decoupled inner and outer external knobs can actuate theinterior lock mechamsm.

When the button 77 is released, then the plate 79 is withdrawn from thenotch 81 in the lock body and rotation of the spindle can ensue in thenormal fashion. That is because the jaw 72 simultaneously engages intoan adjacent notch 52 or does so upon slight rotation of the outer knob46. The outer knob 46 is released for free rotation or spinningsimultaneously upon locking spinning knob assembly in order to get theadded security benefit. The plate 79 responsive to actuation by thebutton 77 is conveniently used as an actuator, but it is also feasibleto arrange motion of the locking bar 71 through a plate 79 or comparabledevice operated from some other remote point.

It is a feature of the present arrangement that a closed end knob neednot be used. The releasable, spinning knob can be employed with thecustomary, key actuated lock mechanism. As shown particularly in FIGS. 5and 6, an outer knob member 91 similar to the outer knob member 46 hassubstantially the same construction as before except that the outercentral portion affords a bowl-like depression 92 for key guidanceThedepression is partly defined by an inner rim 93 interfitting with theinterior margin of the cup 48 in order to stabilize and centralize theseparate parts. The bowl or depression 92 leads to the key end of a keymechanism 94 of any standard sort. A suitable key mechanism 94 includesa generally circular-cylindrical barrel symmetrically disposed withrespect to the axis 17 and in one form has a wing 97 or extensionintegralwith the barrel 96 and projecting radially therefrom. Toaccommodate the wing, the inner, first knob member31 has a longitudinalslot 100 (FIG. 8). The maximum radial exatent of the wing 97 (FIG. 6) issubstantially the same as the diameter of the cylindrical portion 33 sothat the wing is readily housed. The locking mechanism 94 has a plug(not shown in detail) with a key-receiving front plate 98 nested withinthe interior of the bowl 92. The plug also has a driver bar 99 connectedin the customary way to through an aperture 65 inorder to release theknob from the spindle 23. In locked position no depression of the plate101 is possible since the flat driver bar 99- is disposed with its edgeclose to the plate 101. This is shown in Walter R. Schlage US. Pat. No.2,062,765 issuedDec. l, 1936. There is thus provided a keyreceivingexterior knob which can be installed or re-- moved by the use of asingle tool and a proper key and which can be operated from the interiorthrough the bar 78 to be freespinning or to be locked to the spindle.

In some instances it is preferred to make the unitary locking bar 71 asshown in most of the figures, in two pieces, as shown in FIG. 7.'In thisinstance the locking bar 71 as a whole is identical with the previousshowing and description but is inclusive of two portions 71a and 71binterfitted by a tongue and groove joint 71c. The reason for thisseparate construction is that the joint 17c lies close to the margin ofthe'inner knob neck 39. The part 71b can be'detached from the part 71aso as not to project beyond the knob. This protects the parts frominjury during disassembly of the knob and during shop or repairhandling. The part 71b simply resides within'the slot 26 in the spindle,as shown in FIG. 10.

To make sure that the part 71b doe snot at anytime escape when the knobis disassembled, the part 71b carries a tab 7 1e axially movable in acorresponding notch 71f cut in the wall of the spindle 23 alongside thecustomary slot 26. With thisassemblage of the parts,

7 moved and cannot readily fall out or be lost although is shown inFIGS. 11, 12 and Band usually is desired for very heavy dutyinstallations. Many of the parts are just as previously described. Thereis the same spindle 23 rotatable about the axis 17 and having thelongitudi nal slot 26 therein. The same trim 21 is afforded on the doorpanel'7 and the actuating bar 78 is also as before. The spindle containsa locking mechanism 94 connected to a driver bar 99. The present knob 11 l is preferably a solid turning having the desired exterior contour112 and a similar key bowl 92 on the exterior side thereof. The knobterminates in an inner margin 113 defining an opening and cooperatingwith a flange 114 of a shank trim 116. An aperture 117 (shown rotatedout of position) is provided in the trim 116 for the reception of a tooldesigned to displace a knob locking plate 118, as previously described.

The interior of the knob 11 l is provided with a hollow chamber 121having a forward flange 122 surrounding the plug rim 98 of the lock unit94 and has an extra deep bore 123 as well as a counter bore 124.

To mount the knob appropriately on the spindle there is provided aplurality of segments 126 (FIG. 13). Each segment has an arcuateexterior contour 127 and extension 142 is decoupled from the walls ofone of the knob notches 143 and disconnects the knob 111 from thespindle 23. The jaw extension 142 easily disengages while flexing thespring 148. The knob 11] is then free has a chordal extent somethingless than the diameter of the opening defined by the margin 113 of theknob. Each segment 126 is axially extended by a shank 128 having lateralnotches 129 and 121 in the sides thereof. This affords a T-shaped end132 on the segment 126. A number of such segments are introduced throughthe opening defined by the flange 113 and are seated within the counterbore 124 in bearing or rotary relationship therewith.

Each of the segments 126 also rests on the outside of the spindle 23 andis particularly retained in place by having the T-shaped portion 132interfitted with a comparable T-shaped opening 133 formed in a band 1134designed to slip over the spindle. The band 134 also carries an opening136 registering with the opening 117 and designed to receive the lockingplate 118 when such plate is in its radially outermost position. Theband 134 is thus held against rotation and against axial translationwith respect to the spindle and in turn holds each of the segments 126against rotation or axial translation with respect to the spindle.Outward movement of the segments is restrained by the knob 111 and alsoby the trim 114 while inward movement of the segmentsv is restrained bythe spindle itself.

to spin although it is restrained against any axial, relative motion bythe segments 126 in the counter bore 124. When it is desired to recouplethe knob to the spindle, the actuating bar 78 is relaxed toward theright in FIG. 11 and the leaf spring 48 triesto reengage the jawextension 142 with the walls of a knob slot 143. Bither there isimmediate engagement thereof or, upon slight rotation of the knob, thespring leaf 148 snaps the jaw extension 142 into the notch and the knobis firmly coupled to the spindle 23 for solid rotation.

While there has been disclosed herein an outer knob with a key mechanismand releasable for spinning by a control actuated from a location withinan inner knob, the mechanism is also applicable to an arrangement havingtwo knobs each with a key mechanism and effective to couple or uncoupleone or both knobs for spinning either separately or simultaneouslyi Whatis claimed is:

l. A releasable knob' for a lock having a body and having a spindle withan axially extending slot rotatable relative to said body about an axiscomprising a first knob member, means for mounting said first knobmember for rotation about said axis, means for connecting said firstknob member and said" spindle for conjoint rotation about said axis, asecond knob member, means for mounting said second knob member aroundsaid first knob member for rotation relative thereto about said axis,means forming an axially extending first groove in one 'of said knobmembers,

The assembly is preferably made by introducing the several segments,usually four, individually to the unassembled knob through the openingdefined by the margin 113, then moving them axially into position in theplane of the counter bore 124. The band is then positioned on the axisand the segments are moved radially outwardly so that the T-shapedportions 132 fit from inside into the openings 133 as the segments 126enter the bore 124. The spindle is then axially inserted through theband and assists in confining the segments. If the spindle is alreadymounted, the same relative motions are used. The segments act asbearings or shoes and serve as an inner knob for rotation of the outerknob 1 1 1. i

Somewhat as before the knob 111- is coupled and decoupled from thespindle 23 by a locking bar 141 having a stem slidable axially withinthe slot 26 and also having a jaw extension 142. This is axially movableinto any adjacent one of a series of notches 143 in the solid portion ofthe knob 111, as shown in FIG. 11. The lock ing bar is translatable, asbefore, in one of a number of notches 146 in a block 147 correspondingto the inner knob member 31. The jaw extension moves into a dotted lineposition, illustrated in FIG. 11, wherein the jaw extension 142 isdecoupled from the knob receiving notch 143. The locking bar is impelledin one direction by a leaf spring 148 which is secured by a fastener 149(FIG. 12) to the bar and butts against a wall of the counter bore 123.

means forming an axially extending second groove in the other of saidknob members adapted in one relatively rotated position of said knobmembers to be in axial alignment with said first groove, a locking bar,means for mounting said locking'bar in said spindle slot for movement inan axial direction between one position disengnaged from one of saidgrooves and a second I tubular wall with said axially extending slottherein, and

an axis, aknob member, means for mounting said knob member on saidspindle for rotation relative thereto about said axis, first meanseffective in one position for locking said knob member to said spindlefor rotation in unison therewith about said axis and effective in asecond position to free said knob member for rotation thereof about saidaxis independently of said spindle,

and second means effective in one position for locking I tiallysimultaneously operating both of said first and second locking means.

7. A device as in claim including means for simultaneously placing saidfirst locking means in said second position and placing said secondlocking means in said first position.

8. A device as in claim 7 in which said placing means is a membermovable axially within said spindle.

9. A releasable knob adapted for use with a circular spindle rotatableabout a central axis and having an axially extending slot in theperiphery thereof and having a socket in the periphery thereof, a firstknob member having a recess therein and having a circular bore fittingon said spindle for relative axial sliding and rotational movement aboutsaid axis, means fitting said recess and said socket for preventing saidrelative axial and rotational movement of said first knob member andsaid spindle, a second knob member substantially surrounding said firstknob member and rotatable relative thereto about said axis, means forlimiting relative axial movement of said first and second knob members,and means disposed in said slot for limiting relative'rotationalmovement of said first and second knob members. v 10. A releasable knobadapted for use with a hollow spindle rotatable about a central axis andhaving an axially extending slot and an axially extending channeltherein, a circular lock body disposed in said hollow spindle, an axialwing on said lock body extending for a predetermined radial distancetherefrom and disposed in said channel, a first knob member mounted forsubstantially said radial distance to receive said 4 wing, a second knobmember mounted on "said first knob member solely for rotation relativethereto about said axis and overlying said channel, and means at leastpartly in said slot for locking said second knob member against saidrotation on said first knob member.

11. A releasable knob comprising an inner knob portion having a centralbore therein and rotatable about a central axis, an outer knob portionsubstantially surrounding said inner knob portion and rotatable relativeto said inner knob portion about said axis, and means engaging both ofsaid knob portions for holding both of said knob portions againstrelative rotation about said axis, said means being disposed within saidouter knob portion and radially outside of said central bore.

1. A releasable knob for a lock having a body and having a spindle withan axially extending slot rotatable relative to said body about an axiscomprising a first knob member, means for mounting said first knobmember for rotation about said axis, means for connecting said firstknob member and said spindle for conjoint rotation about said axis, asecond knob member, means for mounting said second knob member aroundsaid first knob member for rotation relative thereto about said axis,means forming an axially extending first groove in one of said knobmembers, means forming an axially extending second groove in the otherof said knob members adapted in one relatively rotated position of saidknob members to be in axial alignment with said first groove, a lockingbar, means for mounting said locking bar in said spindle slot formovement in an axial direction between one position disengnaged from oneof said grooves and a second position in engagement with both of saidgrooves.
 2. A device as in claim 1 including means for urging saidlocking bar toward one of said positions, and means movable alongsidesaid axis within said first knob member for overcoming said urging meansand moving said locking bar toward the other of said positions.
 3. Adevice as in claim 1 in which said spindle has a tubular wall with saidaxially extending slot therein, and said locking bar is axially movablein said slot.
 4. A device as in claim 3 in which said slot has apredetermined radial dimension and at least a portion of said lockingbar has approximately the same radial dimension.
 5. A releasable knobfor a lock having a body and having a spindle rotatable relative to saidbody about an axis, a knob member, means for mounting said knob memberon said spindle for rotation relative thereto about said axis, firstmeans effective in one position for locking said knob member to saidspindle for rotation in unison therewith about said axis and effectivein a second position to free said knob member for rotation thereof aboutsaid axis independently of said spindle, and second means effective inone position for locking said spindle to said body against rotation ofsaid spindle about said axis and effective in a second position to freesaid spindle from said body for independent rotation thereof about saidaxis.
 6. A device as in claim 5 including means for substantiallysimultaneously operating both of said first and second locking means. 7.A device as in claim 5 including means for simultaneously placing saidfirst locking means in said second position and placing said secondlocking means in said first position.
 8. A device as in claim 7 in whichsaid placing means is a member movable axially within said spindle.
 9. Areleasable knob adapted for use with a circular spindle rotatable abouta central axis and having an axially extending slot in the peripherythereof and having a socket in the periphery thereof, a first knobmember having a recess therein and having a circular bore fitting onsaid spindle for relative axial sliding and rotational movement aboutsaid axis, means fitting said recess and said socket for preventing saidrelative axial and rotational movement of said first knob member andsaid spindle, a second knob member substantially surrounding said firstknob member and rotatable relative thereto about said axis, means forlimiting relative axial movement of said first and second knob members,and means disposed in said slot for limiting relative rotationalmovement of said first and second knob members.
 10. A releasable knobadapted for use with a hollow spindle rotatable about a central axis andhaving an axially extending slot and an axially extending channeltherein, a circular lock body disposed in said hollow spindle, an axialwing on said lock body extending for a predetermined radial distancetherefrom and disposed in said channel, a first knob member mountedaround said spindle and having an axial slot extending for substantiallysaid radial distance to receive said wing, a second knob member mountedon said first knob member solely for rotation relative thereto aboutsaid axis and overlying said channel, and means at least partly in saidslot for locking said second knob member against said rotation on saidfirst knob member.
 11. A releasable knob comprising an inner knobportion having a central bore therein and rotatable about a centralaxis, an outer knob portion substantially surrounding said inner knobportion and rotatable relative to said inner knob portion about saidaxis, and means engaging both of said knob portions for holding both ofsaid knob portions against relative rotation about said axis, said meansbeing disposed within said outer knob portion and radially outside ofsaid central bore.